mcf5282 Freescale Semiconductor, Inc, mcf5282 Datasheet - Page 432

• Manufacturer Part Number: mcf5282
• Manufacturer: Freescale Semiconductor, Inc

UART Modules
23.3.7
The transmit buffers consist of the transmitter holding register and the transmitter shift register. The
holding register accepts characters from the bus master if UART’s USRn[TXRDY] is set. A write to the
transmit buffer clears USRn[TXRDY], inhibiting any more characters until the shift register can accept
more data. When the shift register is empty, it checks if the holding register has a valid character to be sent
(TXRDY = 0). If there is a valid character, the shift register loads it and sets USRn[TXRDY] again. Writes
to the transmit buffer when the UART’s TXRDY is cleared and the transmitter is disabled have no effect
on the transmit buffer.
Figure 23-9
23.3.8
The UIPCRs hold the current state and the change-of-state for UCTSn.
23-12
IPSBAR
IPSBAR
IPSBAR
Offset:
Offset:
Offset:
Reset:
Reset:
Reset:
W
W
W
R
R
R
UART Transmit Buffers (UTBn)
UART Input Port Change Registers (UIPCRn)
shows UTBn. TB contains the character in the transmit buffer.
0x00_020C (URB0)
0x00_024C (URB1)
0x00_028C (URB2)
0x00_020C (UTB0)
0x00_024C (UTB1)
0x00_028C (UTB2)
0x00_0210 (UIPCR0)
0x00_0250 (UIPCR1)
0x00_0290 (UIPCR2)
1
0
0
0
7
7
7
Figure 23-10. UART Input Port Changed Registers (UIPCRn)
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3
6
1
6
0
6
0
0
Figure 23-9. UART Transmit Buffer (UTBn)
Figure 23-8. UART Receive Buffer (URBn)
1
0
0
0
5
5
5
COS
1
0
0
4
4
4
RB
TB
1
0
1
1
3
3
3
1
0
1
1
2
2
2
Access: User write-only
Access: User read-only
Access: User read-only
Freescale Semiconductor
1
0
1
1
1
1
1
UCTSn
CTS
1
0
0
0
0